2005-04-16 18:20:36 -04:00
|
|
|
/*
|
|
|
|
|
* linux/arch/i386/entry.S
|
|
|
|
|
*
|
|
|
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* entry.S contains the system-call and fault low-level handling routines.
|
|
|
|
|
* This also contains the timer-interrupt handler, as well as all interrupts
|
|
|
|
|
* and faults that can result in a task-switch.
|
|
|
|
|
*
|
|
|
|
|
* NOTE: This code handles signal-recognition, which happens every time
|
|
|
|
|
* after a timer-interrupt and after each system call.
|
|
|
|
|
*
|
|
|
|
|
* I changed all the .align's to 4 (16 byte alignment), as that's faster
|
|
|
|
|
* on a 486.
|
|
|
|
|
*
|
|
|
|
|
* Stack layout in 'ret_from_system_call':
|
|
|
|
|
* ptrace needs to have all regs on the stack.
|
|
|
|
|
* if the order here is changed, it needs to be
|
|
|
|
|
* updated in fork.c:copy_process, signal.c:do_signal,
|
|
|
|
|
* ptrace.c and ptrace.h
|
|
|
|
|
*
|
|
|
|
|
* 0(%esp) - %ebx
|
|
|
|
|
* 4(%esp) - %ecx
|
|
|
|
|
* 8(%esp) - %edx
|
|
|
|
|
* C(%esp) - %esi
|
|
|
|
|
* 10(%esp) - %edi
|
|
|
|
|
* 14(%esp) - %ebp
|
|
|
|
|
* 18(%esp) - %eax
|
|
|
|
|
* 1C(%esp) - %ds
|
|
|
|
|
* 20(%esp) - %es
|
|
|
|
|
* 24(%esp) - orig_eax
|
|
|
|
|
* 28(%esp) - %eip
|
|
|
|
|
* 2C(%esp) - %cs
|
|
|
|
|
* 30(%esp) - %eflags
|
|
|
|
|
* 34(%esp) - %oldesp
|
|
|
|
|
* 38(%esp) - %oldss
|
|
|
|
|
*
|
|
|
|
|
* "current" is in register %ebx during any slow entries.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include <linux/config.h>
|
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
|
#include <asm/thread_info.h>
|
|
|
|
|
#include <asm/errno.h>
|
|
|
|
|
#include <asm/segment.h>
|
|
|
|
|
#include <asm/smp.h>
|
|
|
|
|
#include <asm/page.h>
|
|
|
|
|
#include <asm/desc.h>
|
|
|
|
|
#include "irq_vectors.h"
|
|
|
|
|
|
|
|
|
|
#define nr_syscalls ((syscall_table_size)/4)
|
|
|
|
|
|
|
|
|
|
EBX = 0x00
|
|
|
|
|
ECX = 0x04
|
|
|
|
|
EDX = 0x08
|
|
|
|
|
ESI = 0x0C
|
|
|
|
|
EDI = 0x10
|
|
|
|
|
EBP = 0x14
|
|
|
|
|
EAX = 0x18
|
|
|
|
|
DS = 0x1C
|
|
|
|
|
ES = 0x20
|
|
|
|
|
ORIG_EAX = 0x24
|
|
|
|
|
EIP = 0x28
|
|
|
|
|
CS = 0x2C
|
|
|
|
|
EFLAGS = 0x30
|
|
|
|
|
OLDESP = 0x34
|
|
|
|
|
OLDSS = 0x38
|
|
|
|
|
|
|
|
|
|
CF_MASK = 0x00000001
|
|
|
|
|
TF_MASK = 0x00000100
|
|
|
|
|
IF_MASK = 0x00000200
|
|
|
|
|
DF_MASK = 0x00000400
|
|
|
|
|
NT_MASK = 0x00004000
|
|
|
|
|
VM_MASK = 0x00020000
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
|
|
|
#define preempt_stop cli
|
|
|
|
|
#else
|
|
|
|
|
#define preempt_stop
|
|
|
|
|
#define resume_kernel restore_nocheck
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#define SAVE_ALL \
|
|
|
|
|
cld; \
|
|
|
|
|
pushl %es; \
|
|
|
|
|
pushl %ds; \
|
|
|
|
|
pushl %eax; \
|
|
|
|
|
pushl %ebp; \
|
|
|
|
|
pushl %edi; \
|
|
|
|
|
pushl %esi; \
|
|
|
|
|
pushl %edx; \
|
|
|
|
|
pushl %ecx; \
|
|
|
|
|
pushl %ebx; \
|
|
|
|
|
movl $(__USER_DS), %edx; \
|
|
|
|
|
movl %edx, %ds; \
|
|
|
|
|
movl %edx, %es;
|
|
|
|
|
|
|
|
|
|
#define RESTORE_INT_REGS \
|
|
|
|
|
popl %ebx; \
|
|
|
|
|
popl %ecx; \
|
|
|
|
|
popl %edx; \
|
|
|
|
|
popl %esi; \
|
|
|
|
|
popl %edi; \
|
|
|
|
|
popl %ebp; \
|
|
|
|
|
popl %eax
|
|
|
|
|
|
|
|
|
|
#define RESTORE_REGS \
|
|
|
|
|
RESTORE_INT_REGS; \
|
|
|
|
|
1: popl %ds; \
|
|
|
|
|
2: popl %es; \
|
|
|
|
|
.section .fixup,"ax"; \
|
|
|
|
|
3: movl $0,(%esp); \
|
|
|
|
|
jmp 1b; \
|
|
|
|
|
4: movl $0,(%esp); \
|
|
|
|
|
jmp 2b; \
|
|
|
|
|
.previous; \
|
|
|
|
|
.section __ex_table,"a";\
|
|
|
|
|
.align 4; \
|
|
|
|
|
.long 1b,3b; \
|
|
|
|
|
.long 2b,4b; \
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ENTRY(ret_from_fork)
|
|
|
|
|
pushl %eax
|
|
|
|
|
call schedule_tail
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
popl %eax
|
|
|
|
|
jmp syscall_exit
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Return to user mode is not as complex as all this looks,
|
|
|
|
|
* but we want the default path for a system call return to
|
|
|
|
|
* go as quickly as possible which is why some of this is
|
|
|
|
|
* less clear than it otherwise should be.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
# userspace resumption stub bypassing syscall exit tracing
|
|
|
|
|
ALIGN
|
|
|
|
|
ret_from_exception:
|
|
|
|
|
preempt_stop
|
|
|
|
|
ret_from_intr:
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
movl EFLAGS(%esp), %eax # mix EFLAGS and CS
|
|
|
|
|
movb CS(%esp), %al
|
|
|
|
|
testl $(VM_MASK | 3), %eax
|
|
|
|
|
jz resume_kernel
|
|
|
|
|
ENTRY(resume_userspace)
|
|
|
|
|
cli # make sure we don't miss an interrupt
|
|
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
|
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done on
|
|
|
|
|
# int/exception return?
|
|
|
|
|
jne work_pending
|
|
|
|
|
jmp restore_all
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_PREEMPT
|
|
|
|
|
ENTRY(resume_kernel)
|
|
|
|
|
cli
|
|
|
|
|
cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ?
|
|
|
|
|
jnz restore_nocheck
|
|
|
|
|
need_resched:
|
|
|
|
|
movl TI_flags(%ebp), %ecx # need_resched set ?
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jz restore_all
|
|
|
|
|
testl $IF_MASK,EFLAGS(%esp) # interrupts off (exception path) ?
|
|
|
|
|
jz restore_all
|
|
|
|
|
call preempt_schedule_irq
|
|
|
|
|
jmp need_resched
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
/* SYSENTER_RETURN points to after the "sysenter" instruction in
|
|
|
|
|
the vsyscall page. See vsyscall-sysentry.S, which defines the symbol. */
|
|
|
|
|
|
|
|
|
|
# sysenter call handler stub
|
|
|
|
|
ENTRY(sysenter_entry)
|
|
|
|
|
movl TSS_sysenter_esp0(%esp),%esp
|
|
|
|
|
sysenter_past_esp:
|
|
|
|
|
sti
|
|
|
|
|
pushl $(__USER_DS)
|
|
|
|
|
pushl %ebp
|
|
|
|
|
pushfl
|
|
|
|
|
pushl $(__USER_CS)
|
|
|
|
|
pushl $SYSENTER_RETURN
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Load the potential sixth argument from user stack.
|
|
|
|
|
* Careful about security.
|
|
|
|
|
*/
|
|
|
|
|
cmpl $__PAGE_OFFSET-3,%ebp
|
|
|
|
|
jae syscall_fault
|
|
|
|
|
1: movl (%ebp),%ebp
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,syscall_fault
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
pushl %eax
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
|
|
|
|
|
/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jnz syscall_trace_entry
|
|
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jae syscall_badsys
|
|
|
|
|
call *sys_call_table(,%eax,4)
|
|
|
|
|
movl %eax,EAX(%esp)
|
|
|
|
|
cli
|
|
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
testw $_TIF_ALLWORK_MASK, %cx
|
|
|
|
|
jne syscall_exit_work
|
|
|
|
|
/* if something modifies registers it must also disable sysexit */
|
|
|
|
|
movl EIP(%esp), %edx
|
|
|
|
|
movl OLDESP(%esp), %ecx
|
|
|
|
|
xorl %ebp,%ebp
|
|
|
|
|
sti
|
|
|
|
|
sysexit
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
# system call handler stub
|
|
|
|
|
ENTRY(system_call)
|
|
|
|
|
pushl %eax # save orig_eax
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
# system call tracing in operation / emulation
|
2005-04-16 18:20:36 -04:00
|
|
|
/* Note, _TIF_SECCOMP is bit number 8, and so it needs testw and not testb */
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
testw $(_TIF_SYSCALL_EMU|_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT),TI_flags(%ebp)
|
2005-04-16 18:20:36 -04:00
|
|
|
jnz syscall_trace_entry
|
|
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jae syscall_badsys
|
|
|
|
|
syscall_call:
|
|
|
|
|
call *sys_call_table(,%eax,4)
|
|
|
|
|
movl %eax,EAX(%esp) # store the return value
|
|
|
|
|
syscall_exit:
|
|
|
|
|
cli # make sure we don't miss an interrupt
|
|
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
|
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
testw $_TIF_ALLWORK_MASK, %cx # current->work
|
|
|
|
|
jne syscall_exit_work
|
|
|
|
|
|
|
|
|
|
restore_all:
|
|
|
|
|
movl EFLAGS(%esp), %eax # mix EFLAGS, SS and CS
|
2005-04-16 18:24:01 -04:00
|
|
|
# Warning: OLDSS(%esp) contains the wrong/random values if we
|
|
|
|
|
# are returning to the kernel.
|
|
|
|
|
# See comments in process.c:copy_thread() for details.
|
2005-04-16 18:20:36 -04:00
|
|
|
movb OLDSS(%esp), %ah
|
|
|
|
|
movb CS(%esp), %al
|
|
|
|
|
andl $(VM_MASK | (4 << 8) | 3), %eax
|
|
|
|
|
cmpl $((4 << 8) | 3), %eax
|
|
|
|
|
je ldt_ss # returning to user-space with LDT SS
|
|
|
|
|
restore_nocheck:
|
|
|
|
|
RESTORE_REGS
|
|
|
|
|
addl $4, %esp
|
|
|
|
|
1: iret
|
|
|
|
|
.section .fixup,"ax"
|
|
|
|
|
iret_exc:
|
|
|
|
|
sti
|
2005-04-29 12:38:44 -04:00
|
|
|
pushl $0 # no error code
|
|
|
|
|
pushl $do_iret_error
|
|
|
|
|
jmp error_code
|
2005-04-16 18:20:36 -04:00
|
|
|
.previous
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
ldt_ss:
|
|
|
|
|
larl OLDSS(%esp), %eax
|
|
|
|
|
jnz restore_nocheck
|
|
|
|
|
testl $0x00400000, %eax # returning to 32bit stack?
|
|
|
|
|
jnz restore_nocheck # allright, normal return
|
|
|
|
|
/* If returning to userspace with 16bit stack,
|
|
|
|
|
* try to fix the higher word of ESP, as the CPU
|
|
|
|
|
* won't restore it.
|
|
|
|
|
* This is an "official" bug of all the x86-compatible
|
|
|
|
|
* CPUs, which we can try to work around to make
|
|
|
|
|
* dosemu and wine happy. */
|
|
|
|
|
subl $8, %esp # reserve space for switch16 pointer
|
|
|
|
|
cli
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
/* Set up the 16bit stack frame with switch32 pointer on top,
|
|
|
|
|
* and a switch16 pointer on top of the current frame. */
|
|
|
|
|
call setup_x86_bogus_stack
|
|
|
|
|
RESTORE_REGS
|
|
|
|
|
lss 20+4(%esp), %esp # switch to 16bit stack
|
|
|
|
|
1: iret
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
|
|
|
|
|
|
|
|
|
# perform work that needs to be done immediately before resumption
|
|
|
|
|
ALIGN
|
|
|
|
|
work_pending:
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jz work_notifysig
|
|
|
|
|
work_resched:
|
|
|
|
|
call schedule
|
|
|
|
|
cli # make sure we don't miss an interrupt
|
|
|
|
|
# setting need_resched or sigpending
|
|
|
|
|
# between sampling and the iret
|
|
|
|
|
movl TI_flags(%ebp), %ecx
|
|
|
|
|
andl $_TIF_WORK_MASK, %ecx # is there any work to be done other
|
|
|
|
|
# than syscall tracing?
|
|
|
|
|
jz restore_all
|
|
|
|
|
testb $_TIF_NEED_RESCHED, %cl
|
|
|
|
|
jnz work_resched
|
|
|
|
|
|
|
|
|
|
work_notifysig: # deal with pending signals and
|
|
|
|
|
# notify-resume requests
|
|
|
|
|
testl $VM_MASK, EFLAGS(%esp)
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
jne work_notifysig_v86 # returning to kernel-space or
|
|
|
|
|
# vm86-space
|
|
|
|
|
xorl %edx, %edx
|
|
|
|
|
call do_notify_resume
|
2005-09-11 04:44:45 -04:00
|
|
|
jmp resume_userspace
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ALIGN
|
|
|
|
|
work_notifysig_v86:
|
|
|
|
|
pushl %ecx # save ti_flags for do_notify_resume
|
|
|
|
|
call save_v86_state # %eax contains pt_regs pointer
|
|
|
|
|
popl %ecx
|
|
|
|
|
movl %eax, %esp
|
|
|
|
|
xorl %edx, %edx
|
|
|
|
|
call do_notify_resume
|
2005-09-11 04:44:45 -04:00
|
|
|
jmp resume_userspace
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
# perform syscall exit tracing
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_trace_entry:
|
|
|
|
|
movl $-ENOSYS,EAX(%esp)
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
xorl %edx,%edx
|
|
|
|
|
call do_syscall_trace
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
cmpl $0, %eax
|
2005-09-03 18:57:22 -04:00
|
|
|
jne resume_userspace # ret != 0 -> running under PTRACE_SYSEMU,
|
[PATCH] UML Support - Ptrace: adds the host SYSEMU support, for UML and general usage
Jeff Dike <jdike@addtoit.com>,
Paolo 'Blaisorblade' Giarrusso <blaisorblade_spam@yahoo.it>,
Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Adds a new ptrace(2) mode, called PTRACE_SYSEMU, resembling PTRACE_SYSCALL
except that the kernel does not execute the requested syscall; this is useful
to improve performance for virtual environments, like UML, which want to run
the syscall on their own.
In fact, using PTRACE_SYSCALL means stopping child execution twice, on entry
and on exit, and each time you also have two context switches; with SYSEMU you
avoid the 2nd stop and so save two context switches per syscall.
Also, some architectures don't have support in the host for changing the
syscall number via ptrace(), which is currently needed to skip syscall
execution (UML turns any syscall into getpid() to avoid it being executed on
the host). Fixing that is hard, while SYSEMU is easier to implement.
* This version of the patch includes some suggestions of Jeff Dike to avoid
adding any instructions to the syscall fast path, plus some other little
changes, by myself, to make it work even when the syscall is executed with
SYSENTER (but I'm unsure about them). It has been widely tested for quite a
lot of time.
* Various fixed were included to handle the various switches between
various states, i.e. when for instance a syscall entry is traced with one of
PT_SYSCALL / _SYSEMU / _SINGLESTEP and another one is used on exit.
Basically, this is done by remembering which one of them was used even after
the call to ptrace_notify().
* We're combining TIF_SYSCALL_EMU with TIF_SYSCALL_TRACE or TIF_SINGLESTEP
to make do_syscall_trace() notice that the current syscall was started with
SYSEMU on entry, so that no notification ought to be done in the exit path;
this is a bit of a hack, so this problem is solved in another way in next
patches.
* Also, the effects of the patch:
"Ptrace - i386: fix Syscall Audit interaction with singlestep"
are cancelled; they are restored back in the last patch of this series.
Detailed descriptions of the patches doing this kind of processing follow (but
I've already summed everything up).
* Fix behaviour when changing interception kind #1.
In do_syscall_trace(), we check the status of the TIF_SYSCALL_EMU flag
only after doing the debugger notification; but the debugger might have
changed the status of this flag because he continued execution with
PTRACE_SYSCALL, so this is wrong. This patch fixes it by saving the flag
status before calling ptrace_notify().
* Fix behaviour when changing interception kind #2:
avoid intercepting syscall on return when using SYSCALL again.
A guest process switching from using PTRACE_SYSEMU to PTRACE_SYSCALL
crashes.
The problem is in arch/i386/kernel/entry.S. The current SYSEMU patch
inhibits the syscall-handler to be called, but does not prevent
do_syscall_trace() to be called after this for syscall completion
interception.
The appended patch fixes this. It reuses the flag TIF_SYSCALL_EMU to
remember "we come from PTRACE_SYSEMU and now are in PTRACE_SYSCALL", since
the flag is unused in the depicted situation.
* Fix behaviour when changing interception kind #3:
avoid intercepting syscall on return when using SINGLESTEP.
When testing 2.6.9 and the skas3.v6 patch, with my latest patch and had
problems with singlestepping on UML in SKAS with SYSEMU. It looped
receiving SIGTRAPs without moving forward. EIP of the traced process was
the same for all SIGTRAPs.
What's missing is to handle switching from PTRACE_SYSCALL_EMU to
PTRACE_SINGLESTEP in a way very similar to what is done for the change from
PTRACE_SYSCALL_EMU to PTRACE_SYSCALL_TRACE.
I.e., after calling ptrace(PTRACE_SYSEMU), on the return path, the debugger is
notified and then wake ups the process; the syscall is executed (or skipped,
when do_syscall_trace() returns 0, i.e. when using PTRACE_SYSEMU), and
do_syscall_trace() is called again. Since we are on the return path of a
SYSEMU'd syscall, if the wake up is performed through ptrace(PTRACE_SYSCALL),
we must still avoid notifying the parent of the syscall exit. Now, this
behaviour is extended even to resuming with PTRACE_SINGLESTEP.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-03 18:57:18 -04:00
|
|
|
# so must skip actual syscall
|
2005-04-16 18:20:36 -04:00
|
|
|
movl ORIG_EAX(%esp), %eax
|
|
|
|
|
cmpl $(nr_syscalls), %eax
|
|
|
|
|
jnae syscall_call
|
|
|
|
|
jmp syscall_exit
|
|
|
|
|
|
|
|
|
|
# perform syscall exit tracing
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_exit_work:
|
|
|
|
|
testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl
|
|
|
|
|
jz work_pending
|
|
|
|
|
sti # could let do_syscall_trace() call
|
|
|
|
|
# schedule() instead
|
|
|
|
|
movl %esp, %eax
|
|
|
|
|
movl $1, %edx
|
|
|
|
|
call do_syscall_trace
|
|
|
|
|
jmp resume_userspace
|
|
|
|
|
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_fault:
|
|
|
|
|
pushl %eax # save orig_eax
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
GET_THREAD_INFO(%ebp)
|
|
|
|
|
movl $-EFAULT,EAX(%esp)
|
|
|
|
|
jmp resume_userspace
|
|
|
|
|
|
|
|
|
|
ALIGN
|
|
|
|
|
syscall_badsys:
|
|
|
|
|
movl $-ENOSYS,EAX(%esp)
|
|
|
|
|
jmp resume_userspace
|
|
|
|
|
|
|
|
|
|
#define FIXUP_ESPFIX_STACK \
|
|
|
|
|
movl %esp, %eax; \
|
|
|
|
|
/* switch to 32bit stack using the pointer on top of 16bit stack */ \
|
|
|
|
|
lss %ss:CPU_16BIT_STACK_SIZE-8, %esp; \
|
|
|
|
|
/* copy data from 16bit stack to 32bit stack */ \
|
|
|
|
|
call fixup_x86_bogus_stack; \
|
|
|
|
|
/* put ESP to the proper location */ \
|
|
|
|
|
movl %eax, %esp;
|
|
|
|
|
#define UNWIND_ESPFIX_STACK \
|
|
|
|
|
pushl %eax; \
|
|
|
|
|
movl %ss, %eax; \
|
|
|
|
|
/* see if on 16bit stack */ \
|
|
|
|
|
cmpw $__ESPFIX_SS, %ax; \
|
|
|
|
|
jne 28f; \
|
|
|
|
|
movl $__KERNEL_DS, %edx; \
|
|
|
|
|
movl %edx, %ds; \
|
|
|
|
|
movl %edx, %es; \
|
|
|
|
|
/* switch to 32bit stack */ \
|
|
|
|
|
FIXUP_ESPFIX_STACK \
|
|
|
|
|
28: popl %eax;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Build the entry stubs and pointer table with
|
|
|
|
|
* some assembler magic.
|
|
|
|
|
*/
|
|
|
|
|
.data
|
|
|
|
|
ENTRY(interrupt)
|
|
|
|
|
.text
|
|
|
|
|
|
|
|
|
|
vector=0
|
|
|
|
|
ENTRY(irq_entries_start)
|
|
|
|
|
.rept NR_IRQS
|
|
|
|
|
ALIGN
|
|
|
|
|
1: pushl $vector-256
|
|
|
|
|
jmp common_interrupt
|
|
|
|
|
.data
|
|
|
|
|
.long 1b
|
|
|
|
|
.text
|
|
|
|
|
vector=vector+1
|
|
|
|
|
.endr
|
|
|
|
|
|
|
|
|
|
ALIGN
|
|
|
|
|
common_interrupt:
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
movl %esp,%eax
|
|
|
|
|
call do_IRQ
|
|
|
|
|
jmp ret_from_intr
|
|
|
|
|
|
|
|
|
|
#define BUILD_INTERRUPT(name, nr) \
|
|
|
|
|
ENTRY(name) \
|
|
|
|
|
pushl $nr-256; \
|
|
|
|
|
SAVE_ALL \
|
|
|
|
|
movl %esp,%eax; \
|
|
|
|
|
call smp_/**/name; \
|
|
|
|
|
jmp ret_from_intr;
|
|
|
|
|
|
|
|
|
|
/* The include is where all of the SMP etc. interrupts come from */
|
|
|
|
|
#include "entry_arch.h"
|
|
|
|
|
|
|
|
|
|
ENTRY(divide_error)
|
|
|
|
|
pushl $0 # no error code
|
|
|
|
|
pushl $do_divide_error
|
|
|
|
|
ALIGN
|
|
|
|
|
error_code:
|
|
|
|
|
pushl %ds
|
|
|
|
|
pushl %eax
|
|
|
|
|
xorl %eax, %eax
|
|
|
|
|
pushl %ebp
|
|
|
|
|
pushl %edi
|
|
|
|
|
pushl %esi
|
|
|
|
|
pushl %edx
|
|
|
|
|
decl %eax # eax = -1
|
|
|
|
|
pushl %ecx
|
|
|
|
|
pushl %ebx
|
|
|
|
|
cld
|
|
|
|
|
pushl %es
|
|
|
|
|
UNWIND_ESPFIX_STACK
|
|
|
|
|
popl %ecx
|
|
|
|
|
movl ES(%esp), %edi # get the function address
|
|
|
|
|
movl ORIG_EAX(%esp), %edx # get the error code
|
|
|
|
|
movl %eax, ORIG_EAX(%esp)
|
|
|
|
|
movl %ecx, ES(%esp)
|
|
|
|
|
movl $(__USER_DS), %ecx
|
|
|
|
|
movl %ecx, %ds
|
|
|
|
|
movl %ecx, %es
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call *%edi
|
|
|
|
|
jmp ret_from_exception
|
|
|
|
|
|
|
|
|
|
ENTRY(coprocessor_error)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_coprocessor_error
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(simd_coprocessor_error)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_simd_coprocessor_error
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(device_not_available)
|
|
|
|
|
pushl $-1 # mark this as an int
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
movl %cr0, %eax
|
|
|
|
|
testl $0x4, %eax # EM (math emulation bit)
|
|
|
|
|
jne device_not_available_emulate
|
|
|
|
|
preempt_stop
|
|
|
|
|
call math_state_restore
|
|
|
|
|
jmp ret_from_exception
|
|
|
|
|
device_not_available_emulate:
|
|
|
|
|
pushl $0 # temporary storage for ORIG_EIP
|
|
|
|
|
call math_emulate
|
|
|
|
|
addl $4, %esp
|
|
|
|
|
jmp ret_from_exception
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Debug traps and NMI can happen at the one SYSENTER instruction
|
|
|
|
|
* that sets up the real kernel stack. Check here, since we can't
|
|
|
|
|
* allow the wrong stack to be used.
|
|
|
|
|
*
|
|
|
|
|
* "TSS_sysenter_esp0+12" is because the NMI/debug handler will have
|
|
|
|
|
* already pushed 3 words if it hits on the sysenter instruction:
|
|
|
|
|
* eflags, cs and eip.
|
|
|
|
|
*
|
|
|
|
|
* We just load the right stack, and push the three (known) values
|
|
|
|
|
* by hand onto the new stack - while updating the return eip past
|
|
|
|
|
* the instruction that would have done it for sysenter.
|
|
|
|
|
*/
|
|
|
|
|
#define FIX_STACK(offset, ok, label) \
|
|
|
|
|
cmpw $__KERNEL_CS,4(%esp); \
|
|
|
|
|
jne ok; \
|
|
|
|
|
label: \
|
|
|
|
|
movl TSS_sysenter_esp0+offset(%esp),%esp; \
|
|
|
|
|
pushfl; \
|
|
|
|
|
pushl $__KERNEL_CS; \
|
|
|
|
|
pushl $sysenter_past_esp
|
|
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(debug)
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $sysenter_entry,(%esp)
|
|
|
|
|
jne debug_stack_correct
|
|
|
|
|
FIX_STACK(12, debug_stack_correct, debug_esp_fix_insn)
|
|
|
|
|
debug_stack_correct:
|
|
|
|
|
pushl $-1 # mark this as an int
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # error code 0
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_debug
|
|
|
|
|
jmp ret_from_exception
|
2005-09-06 18:19:27 -04:00
|
|
|
.previous .text
|
2005-04-16 18:20:36 -04:00
|
|
|
/*
|
|
|
|
|
* NMI is doubly nasty. It can happen _while_ we're handling
|
|
|
|
|
* a debug fault, and the debug fault hasn't yet been able to
|
|
|
|
|
* clear up the stack. So we first check whether we got an
|
|
|
|
|
* NMI on the sysenter entry path, but after that we need to
|
|
|
|
|
* check whether we got an NMI on the debug path where the debug
|
|
|
|
|
* fault happened on the sysenter path.
|
|
|
|
|
*/
|
|
|
|
|
ENTRY(nmi)
|
|
|
|
|
pushl %eax
|
|
|
|
|
movl %ss, %eax
|
|
|
|
|
cmpw $__ESPFIX_SS, %ax
|
|
|
|
|
popl %eax
|
|
|
|
|
je nmi_16bit_stack
|
|
|
|
|
cmpl $sysenter_entry,(%esp)
|
|
|
|
|
je nmi_stack_fixup
|
|
|
|
|
pushl %eax
|
|
|
|
|
movl %esp,%eax
|
|
|
|
|
/* Do not access memory above the end of our stack page,
|
|
|
|
|
* it might not exist.
|
|
|
|
|
*/
|
|
|
|
|
andl $(THREAD_SIZE-1),%eax
|
|
|
|
|
cmpl $(THREAD_SIZE-20),%eax
|
|
|
|
|
popl %eax
|
|
|
|
|
jae nmi_stack_correct
|
|
|
|
|
cmpl $sysenter_entry,12(%esp)
|
|
|
|
|
je nmi_debug_stack_check
|
|
|
|
|
nmi_stack_correct:
|
|
|
|
|
pushl %eax
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_nmi
|
|
|
|
|
jmp restore_all
|
|
|
|
|
|
|
|
|
|
nmi_stack_fixup:
|
|
|
|
|
FIX_STACK(12,nmi_stack_correct, 1)
|
|
|
|
|
jmp nmi_stack_correct
|
|
|
|
|
nmi_debug_stack_check:
|
|
|
|
|
cmpw $__KERNEL_CS,16(%esp)
|
|
|
|
|
jne nmi_stack_correct
|
2005-11-13 19:06:52 -05:00
|
|
|
cmpl $debug,(%esp)
|
|
|
|
|
jb nmi_stack_correct
|
2005-04-16 18:20:36 -04:00
|
|
|
cmpl $debug_esp_fix_insn,(%esp)
|
2005-11-13 19:06:52 -05:00
|
|
|
ja nmi_stack_correct
|
2005-04-16 18:20:36 -04:00
|
|
|
FIX_STACK(24,nmi_stack_correct, 1)
|
|
|
|
|
jmp nmi_stack_correct
|
|
|
|
|
|
|
|
|
|
nmi_16bit_stack:
|
|
|
|
|
/* create the pointer to lss back */
|
|
|
|
|
pushl %ss
|
|
|
|
|
pushl %esp
|
|
|
|
|
movzwl %sp, %esp
|
|
|
|
|
addw $4, (%esp)
|
|
|
|
|
/* copy the iret frame of 12 bytes */
|
|
|
|
|
.rept 3
|
|
|
|
|
pushl 16(%esp)
|
|
|
|
|
.endr
|
|
|
|
|
pushl %eax
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
FIXUP_ESPFIX_STACK # %eax == %esp
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
call do_nmi
|
|
|
|
|
RESTORE_REGS
|
|
|
|
|
lss 12+4(%esp), %esp # back to 16bit stack
|
|
|
|
|
1: iret
|
|
|
|
|
.section __ex_table,"a"
|
|
|
|
|
.align 4
|
|
|
|
|
.long 1b,iret_exc
|
|
|
|
|
.previous
|
|
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(int3)
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $-1 # mark this as an int
|
|
|
|
|
SAVE_ALL
|
|
|
|
|
xorl %edx,%edx # zero error code
|
|
|
|
|
movl %esp,%eax # pt_regs pointer
|
|
|
|
|
call do_int3
|
|
|
|
|
jmp ret_from_exception
|
2005-09-06 18:19:27 -04:00
|
|
|
.previous .text
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(overflow)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_overflow
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(bounds)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_bounds
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(invalid_op)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_invalid_op
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(coprocessor_segment_overrun)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_coprocessor_segment_overrun
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(invalid_TSS)
|
|
|
|
|
pushl $do_invalid_TSS
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(segment_not_present)
|
|
|
|
|
pushl $do_segment_not_present
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
|
|
|
|
ENTRY(stack_segment)
|
|
|
|
|
pushl $do_stack_segment
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(general_protection)
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_general_protection
|
|
|
|
|
jmp error_code
|
2005-09-06 18:19:27 -04:00
|
|
|
.previous .text
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
ENTRY(alignment_check)
|
|
|
|
|
pushl $do_alignment_check
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
2005-09-06 18:19:27 -04:00
|
|
|
KPROBE_ENTRY(page_fault)
|
2005-04-16 18:20:36 -04:00
|
|
|
pushl $do_page_fault
|
|
|
|
|
jmp error_code
|
2005-09-06 18:19:27 -04:00
|
|
|
.previous .text
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
#ifdef CONFIG_X86_MCE
|
|
|
|
|
ENTRY(machine_check)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl machine_check_vector
|
|
|
|
|
jmp error_code
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
ENTRY(spurious_interrupt_bug)
|
|
|
|
|
pushl $0
|
|
|
|
|
pushl $do_spurious_interrupt_bug
|
|
|
|
|
jmp error_code
|
|
|
|
|
|
2006-01-06 03:12:05 -05:00
|
|
|
.section .rodata,"a"
|
2005-05-01 11:58:55 -04:00
|
|
|
#include "syscall_table.S"
|
2005-04-16 18:20:36 -04:00
|
|
|
|
|
|
|
|
syscall_table_size=(.-sys_call_table)
|
